Industrial electric furnace with movable hearths for burning of concentrates and conglomerates of vermiculite ores

Introduction. The electric furnaces with movable hearth platforms using allows to reduce the vermiculite firing energy consumption to 80 mJ/m3. Purpose of the research. Ensuring stationary movement of vermiculite in the firing zone and creating an industrial electric furnace with dynamically balanced platforms. Materials and methods. Analytical and experimental methods, results obtained on different vermiculite concentrates were used. Results. The proposed design provides dynamic balance of the moving elements of the furnace. When combining two power units, the specific energy intensity of firing remains unchanged – 63.7...81.8 mJ/m3, while the twin industrial furnace has a capacity of 7.5 m3/h. The ranges of setting the angle of modules inclination are set – 18...20°, oscillation frequency – 7...8.5 Hz, firing time – 3...4 s. Discussion. In the original design, the hearth platform has a high sensitivity to minor fluctuations in the excitation frequency. Its new design – with kinematic excitation and ensures stable movement of both the platforms and the heattreated material. The developed industrial electric furnace allows increasing productivity to 7.5 m3/h, while maintaining the specific energy intensity of the process unchanged. Conclusion. The initial firing module design rationalization ensured the achievement of stationary characteristics of the platforms and fired material motion. The principle of pairing power units simplifies the furnace design unit as a whole. The paired installation of eccentrics creates a dynamic equilibrium of the furnace, when the resultant of the inertial forces of each pair of eccentrics and the inertial forces of the platforms are equal to zero. Resume. The results of studies of a new firing module and a twin six-module furnace are presented. The research results can be useful in creating industrial electric furnaces for firing vermiculite concentrates. Also they can be used as a basis for the design methodology of twin three-module electric furnaces for roasting vermiculite ores concentrates. However, the main direction of the search is to reduce the specific energy consumption of vermiculite roasting.